The present invention relates to wireless communications in general, and, in particular, relates to techniques for managing mobile terminal operations in multiple service provider areas.
Growth in consumer demand for wireless communication services continues unabated. This consumer demand drives technological innovation as service providers search for ways to support rapidly growing number of customers competing for the finite bandwidth available to the service providers. The demand also stimulates the creation of new service providers, and compels existing service providers to compete for customers within the same service areas.
The intelligent roaming provisions within the TIA/EIA-136 standard govern the manner in which a given mobile terminal acquires or changes service from one service provider to the next. Service providers are generally ranked in terms of priority, with the overall scheme being that the mobile terminal uses the highest priority service provider available. The service provider from whom a given user contracted for wireless service is normally considered that user""s xe2x80x9chomexe2x80x9d service provider. The home provider may have arrangements with other service providers, called xe2x80x9cpartnerxe2x80x9d service providers, which permit its users to access a partner service provider""s network in areas where the home service provider does not provide coverage. Other typical service provider categories include favored, neutral, and forbidden, with such designations being descriptive of the priorities the user""s mobile terminal should apply when attempting to secure service in a given coverage area.
Often, multiple service providers operate within a given coverage area. When mobile terminal users operate their mobile terminals in such areas, their mobile terminals face the challenge of acquiring and maintaining service from the most appropriate service provider operating within the area. The number of service providers operating within a given coverage area can be significant. For example, the TIA/EIA-136 standard defines digital cellular telephone service for both the 800 MHz and 1900 MHz spectrums. The 800 MHz spectrum, referred to as the 800 MHz hyperband, has two standard bands, A and B. The 1900 MHz spectrum, referred to as the 1900 MHz hyperband, has six standard bands, A-F. A number of standard radio channels (frequencies) are included in each of the standard bands within these hyperbands.
Normally, in a given geographic area, there are up to two different service providers in the 800 MHz hyperband, each occupying one of the two standard 800 MHz bands. Similarly, within the same service area, there are up to six different service providers in the 1900 MHz hyperband, each occupying one of the six standard 1900 MHz bands. However, the TIA/EIA-136 standard permits up to 64 different service providers to operate in each of the hyperbands. In these circumstances, each service provider is allocated a certain number of the standard radio channels within the hyperband in which they operate. The TIA/EIA-136 standard defines a Regulatory Control Message that informs mobile terminals within the service area as to whether the standard bands within the hyperband in which the mobile terminal operates are further subdivided to support more than the standard number of carriers.
The present invention is a system and method for controlling a mobile terminal such that it seeks the highest priority service provider available in an area served by multiple service providers, without dropping its current service connection. In stand-by, the mobile terminal camps on a service provider control channel. The mobile terminal monitors control channel information for an indication that the standard bands of the current hyperband are redefined to support additional service providers. Upon such indication, and if not already camped on the mobile terminal""s home service provider, the mobile terminal begins background scanning operations. Background scanning allows the mobile terminal to look for the highest priority service provider available, without dropping its current control channel. The scanning process is interruptible and transparent to the user of the mobile terminal.
In a TIA/EIA-136 environment, the mobile terminal operates in a given one of the 800 MHz and 1900 MHz hyperbands, and camps on a digital control channel (DCCH) if available. Extended Broadcast Channel (E-BCCH) information indicates whether the standard bands within the current hyperband redefined configured to support more than customary one service provider per standard band. This information comes in the form of a Regulatory Control Indicator (RCI) included in an associated Regulatory Control Message. If the RCI indicates that the standard bands within the current hyperband are redefined, it also contains additional information about how the standard radio channels within the current hyperband are allocated to the available service providers.
With this channel allocation information for the current hyperband, the mobile terminal may begin background scanning of the current hyperband for higher priority service providers, and may additionally do a background check of the other hyperband to determine the standard bands of the other hyperband are also redefined to support multiple service providers. If the alternate hyperband also provides two or more service providers within one or more of its standard bands, i.e., its standard bands have been redefined, the mobile terminal may extend background scanning operations to the other hyperband to see if a higher priority service provider is available within it.